The present application is directed to electromagnetic railguns, and more particularly to projectiles launched from electromagnetic railguns.
Electromagnetic railguns utilize an electromagnetic force called the Lorentz force to propel an electrically conductive integrated launch package (ILP). In a typical electromagnetic railgun, the ILP slides between two parallel rails and acts as a sliding switch or electrical short between the rails. By passing a large electrical current down one rail, through the ILP, and back along the other rail, a large magnetic field is built up behind the ILP, accelerating it to a high velocity by the force of the current times the magnetic field. An electromagnetic railgun is capable of launching an ILP to velocities greater than fielded powder guns, thereby achieving greater ranges and shorter flight times to engagement.
An ILP typically includes three subsystems: (1) the armature; (2) the sabot; and (3) the projectile. The armature and sabot often comprise about 30- to 50-percent of the total ILP mass. However, these components are traditionally only used during the launch process and are immediately discarded after bore disengagement. Thus, the projectile, which includes the lethality mechanism among other components, often comprises only about 50- to 70-percent of the total ILP mass. Accordingly, one drawback associated with electromagnetic railguns is that insufficient lethality mass is delivered to the target when compared with conventional powder guns and tactical missiles.
In addition, for launch velocities greater than about 2.2 km/s, the armature can transition, thereby inducing undesirable in-bore lateral loads to the ILP and reducing rail life. By reducing launch velocity (e.g., to about 1.7 km/s), heavier ILPs can be launched without experiencing armature transition. However, this approach results in a reduced engagement range for the electromagnetic railgun.